> I wonder if any of these have four or more simple characters jammed into one.

yup!

https://en.m.wikipedia.org/wiki/Radical_(Chinese_characters)

> For example, the radical 女 appears on the left side in the characters 姐, 媽, 她, 好 and 姓

That's about what I meant, but so far I've seen three-part characters and am sorta curious how many more get used, in practice. Also afaik some radicals get chopped in the process, and it seems there are some rudimentary ones (in terms of graphics) that aren't ever used on their own—both of which don't present much of a challenge so I'd count them as half a part for my purposes.

11: https://en.wikipedia.org/wiki/Biangbiang_noodles

Impressive. Would pinyin for entering the full symbol also be as elaborate as the sum of the parts, or is just ‘biángbiángmiàn’? Though I suspect that this character is where the ‘in practice’ condition kicks in.

Notably, in the mnemonic for the character I see another one that has four parts, exceeding my previous experience: 彎.

Also the PDF for the Source Han Sans font, linked in the Wikipedia article, has right under the biángbiángmiàn some other monstrosity, consisting of 18 parts if I'm seeing them right. Of course, it's likely another novelty thing: https://raw.githubusercontent.com/adobe-fonts/source-han-san...

Seems that the latter if ‘Taito’: https://en.wikipedia.org/wiki/Taito_(kanji)

As the readme for Source Han Sans mentions, neither of these characters is encoded in Unicode yet, so writing them isn't supported by most input methods. (Wikipedia uses SVGs to show the characters; the font recognizes the ideographic description sequence.)

However, once support arrives, it will be as easy as typing "biang", since there's currently no character with that pronunciation. It could be confused with a two-syllable word "bi ang", but there's no such word in Mandarin.